Apparatus for stacking sheets

ABSTRACT

In a sheet stacking apparatus producing multiple stacks with dividing plates between adjacent stacks, the dividing plates are made of plastic material, preferably an epoxy/glass laminate.

United States Patent Inventor John P. Bennett Summerstown, London, England Appl. No 762,596 Filed Sept. 25, 1968 Patented June 1, 1971 Assignee Masson Scott Thrissell Engineering Limited London, England Priority Sept. 27, 1967 Great Britain 43951/67 APPARATUS FOR STACKING SHEETS 4 Claims, 1 Drawing Fig.

[56] References Cited UNITED STATES PATENTS 2,930,493 3/1960 Sundblad et a1. 4. 2l4/6(M )X 2,961,086 11/1960 Edis 214/6(D)X 3,007,591 11/1961 Sundblad 214/6(D)X 3,180,066 4/1965 Mahaffy et a1. 53/52 3,358,993 12/1967 Lytle 214/6(D) FOREIGN PATENTS 1,014,040 12/19 6; Great Britain 214/6(D) Primary ExaminerGerald M. Forlenza Assistant ExaminerRobert J. Spar AttorneyCraig, Antonelli, Stewart & Hill ABSTRACT: In a sheet stacking apparatus producing multiple stacks with dividing plates between adjacent stacks, the dividing plates are made of plastic material, preferably an epoxy/glass laminate.

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APPARATUS FOR STACKING SHEETS This invention concerns improvements in or relating to apparatus for stacking sheets.

In the production of sheets of paper it is common practice to slit a moving paper web along its length to provide, in effect, a plurality of side-by-side lengthwise moving webs, and then to c'rosscut the webs to sever sheets therefrom. The sheets are then delivered to a layboy to form a plurality of side-by-side stacks corresponding to said plurality of webs, the sheets lying horizontally one on top of another in each stack. Relative movement between the layboy and the sheet delivery means is effected as the height of the stacks increases so that the sheets are delivered at the level of the top of the stacks, either by gradually raising the delivery means or by gradually lowering the layboy. To maintain proper separation between the stacks and to achieve the formation of even stacks with vertical sides vertically disposed dividing plates are normally provided in conjunction with the sheet delivery means and arranged so that a dividing plate is positioned between each pair of adjacent stacks, the dividing plates normally being vibrated to assist in settling the delivered sheets on to the stacks. An example of apparatus for stacking sheets using vibrating dividing plates is disclosed in British Patent Specification No. 1,014,040, published Dec. 22, 1965. Conventionally the dividing plates are made of metal such as steel.

According to the present invention there is provided apparatus for stacking sheets comprising sheet delivery means arranged to deliver sheets in side-by-side arrangement to receiving means on which the sheets form a plurality of sideby-side stacks, and one or more dividing plates so disposed that a dividing plate is positioned between each pair of adjacent stacks, wherein the material of the dividing plate or plates is of a plastic material.

The use of dividing plates of plastic material has been found to give surprisingly good stacking of paper sheets. Although, as will now beexplained, certain advantages may be seen to result from the known properties of plastic materials, it appears that the overall effect of using plastic dividing plates in sheet stacking apparatus is beneficial to an unexpected degree.

The resilience of a plastic dividing plate enables it to reassume its original shape after it is subjected to an unintentional bending pressure, or, if it is bent beyond its elastic limit, the plastic plate will normally break. in this latter case the remaining portion from which part of the plate has been broken will usually be straight and may still be sufficient to serve the required purpose and maintain the proper formation of the stacks. If the remaining portion is insufficient for this purpose, then it will probably completely prevent the formation of the required separate stacks. In other words, a plastic dividing plate is most unlikely to lead to malformed stacks as can occur with a conventional metal dividing plate which has become bent and is difficult to straighten.

Means may be provided to vibrate the plastic dividing plate or plates, and preferably such means comprise a pneumatic vibrator. A plastic plate which is lighter than the conventional metal plate can react more favorably to a pneumatic vibrator sinceless air needs to be used to effect the vibration. Further, the vibration of a plastic plate normally produces less noise than the vibration of a metal plate, although in practice the stack formationappears to be better.

A light plastic plate is generally easier to handle than a heavier metal plate, and, due to the lesser density of plastics as compared with metal, the plastics dividing plate can, if desired, be made thicker than the conventional metal plates to effect a greater separation between the adjacent stacks.

Plastics can normally more easily be kept clean than metal and whereas with metal dividing plates there is sometimes a risk of the sheets being marked by the plates, particularly when high grade papers are being handled, there is less likelihood of such marking with plastic dividing plates. Further, plastics having a smooth slippery surface can assist the flow of paper sheets, and a plastic plate is less likely to burr than is metal. Also, plastic material does not normally tarnish and can be resistant to corrosion. The plastics can be antistatic to prevent the collection of electrostatic charges, and consequent accumulation of dust and small particles thereon.

If desired, the plastic dividing plate or plates can be transparent so that the stacks can be seen through the dividing plate or plates, for example to see if any of the stacked sheets have had their corners bent over.

Where long sheets are to be handled a long dividing plate of plastic can be provided and maintained in its straight smooth state, whereas a long conventional dividing plate of metal can very easily become bent and unsatisfactory. if desired, however, where long sheets are to be handled there may be provided two aligned dividing plates of plastic positioned between each pair of adjacent stacks.

The plastic dividing plate or plates can conveniently be manufactured either by moulding or by cutting from plastic sheet.

The plastic material of the dividing plate or plates may be a laminate, for example, epoxy glass cloth laminate, epoxy/glass laminate or glass fibre and polyester laminate, or may be homogeneous.

Apparatus in accordance with the invention will now be described, by way of example, with reference to the accompanying drawing which is a side elevation of apparatus for stacking paper sheets.

Sheets of paper are fed, in side-by-side arrangement,

between endless moving conveyor belts l and 2 passing round rollers 3 and rollers 4 and 5 respectively. The sheets are produced by slitting a moving paper web lengthwise to produce, in effect, a plurality of side-by-side lengthwise moving webs, and then cross-cutting these webs to produce the sheets. The leading end of each sheet is caused to overlap the trailing end of the preceding sheet in known manner. Thus the belts l and 2 convey a plurality of succession of sheets, the sheets in each succession being in the overlapping relationship explained above, and the successions being arranged sidebyside.

The sheets pass from the belt 2 over a bridge 6 and between a lower roller 7 and an upper endless belt 8. The belt 8 passes round a driving roller 9, whose height above the roller 7 is adjustable to increase or decrease the nip between the roller 7 and belt 8 as required, and a return roller 10 located above the roller 5.

The rollers 5, 7, 9 and 10 are mounted on a block 11 which can be raised and lowered by means of a cable 12 connected to the block and operated by a jack 13. The rollers 3 and 4 are mounted on a support 14 which connects with a pivot 15 at one end of an arm 16 which is attached by a pivot 17 to the block 11. The end of the support 14 remote from the pivot 15 and not shown in the drawing is also pivoted. By these connections raising and lowering of the block 11 causes corresponding raising and lowering of the support 14 so that the sheets are delivered between the roller 7 and belt 8 whatever the height of the block 11.

The sheets fed between the roller 7 and belt 8 are received on a layboy having a stationary base 18 on which the sheets form a plurality of side-by-side stacks S corresponding to the plurality of side-by-side successions of sheets being fed. The overlapping relationship of the sheets in each succession explained above ensures that each sheet travels over the preceding sheet as the sheets are received on the stack.

When the stacks are first started the block 11, and hence the level of delivery of the sheets between the roller 7 and belt 8, is at its lowest position and as the height of the stacks increases the block 11 is gradually raised, by means of the jack 13 and cable 12, to keep the level of sheet delivery a short distance above the top of the stacks.

A series of vertical dividing plates 19 are carried by arms 20 mounted on a rod 21 connected to the block 11. The dividing plates 19 are disposed in spaced relationship in a direction normal to the plane of the drawing so that a dividing plate 19 is positioned between each pair of adjacent stacks S. The disposition of the plates 19 along the rod 21 can be adjusted so that the apparatus can accommodate different stack widths. Each plate 19 is vibrated by means of a pneumatic vibrator 22 operated from an air device 23 through a pipe 24 in a manner as described in the aforementioned patent specification. The plates 19 serve to maintain a proper separation between the stacks S and to achieve the formation of even stacks. The dividing plates 19 are made of plastic material known as PERMAGLASS 22 FE," an epoxy-glass cloth laminate supplied by Permali Limited of Gloucester, Eng. and having a high mechanical and flexural strength of about 60,000 lb-ft per square inch using a sample one-eighth inch long and 3 millimeters thick.

A series of further vertical dividing plates 25 are carried by arms 26 mounted on a back board 27 of the layboy. The plates 25 are spaced in the same manner as the plates 19 so that a dividing plate 25 is positioned, in alignment with a plate 19, between each pair of adjacent stacks S.

The backboard 27 is carried on supporting bars 28 which are connected to the block ll so that the backboard, and the plates 25 are raised as the block 11 is raised. The backboard 27 is positioned so that the sheets delivered to the layboy abut against it and settle on the stacks. The plates 19, being connected to the block 11, also rise as the block rises.

The plates 25, like the plates 19, are made of the plastic material known as PERMAGLASS 22 FE.

Two aligned dividing plates between each pair of adjacent stacks, as shown and described, are provided to enable the apparatus to stack long sheets. It will be appreciated that if desired, a single dividing plate only may be provided between each pair of adjacent stacks.

It will further be appreciated that the provision of plastic dividing plates in accordance with the invention is also applicable to sheet stacking apparatus in which the sheets are delivered at a constant level and the base of the layboy is lowered to maintain the required relationship between the delivery level and the top of the stacks, as well as to apparatus in which the delivery level is raised as the height of the stacks increases as in the particular embodiment described.

What I claim as my invention and desire to secure by Letters Patent is:

1. Apparatus for stacking sheets comprising sheet delivery means arranged to deliver sheets horizontally in side-by-side arrangement to receiving means on which the sheets form a plurality of side-by-side stacks, and at least one dividing plate vertically positioned between stacks to separate adjacent stacks as they are formed, the material of the dividing plate being a plastic synthetic resin-glass fiber material, and means for vibrating the dividing plate.

2. Apparatus as claimed in claim 1, in which the material is an epoxy/glass cloth laminate.

3. Apparatus as claimed in claim 1, in which the material is a glass fibre and polyester laminate.

4. Apparatus as claimed in claim 1, in which the material is an epoxy/glass laminate. 

1. Apparatus for stacking sheets comprising sheet delivery means arranged to deliver sheets horizontally in side-by-side arrangement to receiving means on which the sheets form a plurality of side-by-side stacks, and at least one dividing plate vertically positioned between stacks to separate adjacent stacks as they are formed, the material of the dividing plate being a plastic synthetic resin-glass fiber material, and means for vibrating the dividing plate.
 2. Apparatus as claimed in claim 1, in which the material is an epoxy/glass cloth laminate.
 3. Apparatus as claimed in claim 1, in which the material is a glass fibre and polyester laminate.
 4. Apparatus as claimed in claim 1, in which the material is an epoxy/glass laminate. 